Federal and state governments have enacted progressive laws and regulations that impose ever-increasing restrictions on motor vehicles in the areas of exhaust emissions and improved fuel economy. For example, the California regulations include Super Ultra Low Emission Vehicle (SULEV) emission standards. It is noted that SULEV emission standards are particularly more stringent on hydrocarbon (HC) and nitrogen oxides (NOx) emissions. Moreover, as this trend of increasingly restrictive emissions continues, Zero Emission Vehicle (ZEV) standards are eventually going to become the standard for exhaust gaseous emissions.
Transportation engine systems (compression ignition engines, and the like) for vehicle systems (e.g., passenger cars, trucks, and the like) can draw significant emissions benefits from fuel enrichment with hydrogen and/or carbon monoxide. More particularly, hydrogen- and/or carbon monoxide-enriched fuels can promote rapid catalyst heating to improve exhaust catalyst light-off time, thereby reducing hydrocarbon and NOx emission, and the like. Moreover, it is noted that hydrogen- and/or carbon monoxide-enriched fuel can cause an engine to operate cleaner under various steady state and transient operating conditions via the control of the fuel mixture, timing, and other combustion parameters, thus promoting more complete and cleaner combustion compared to an engine operating with non-hydrogen enriched and/or non-carbon monoxide enriched fuels.
What is need in the art are methods of operating a compression ignition engine and vehicle system that can result in cleaner exhaust.